Heat oil in large pot or Dutch oven over medium heat.

Add onion and saute until golden, about 5 minutes.

Add garlic, curry, cumin and ginger. Saute just until fragrant.

Add tomato paste and arrowroot. Stir to combine.

Slowly whisk in broth, increase heat to high and bring to a boil.

Reduce heat to low and simmer 20 minutes, stirring occasionally, until sauce thickens slightly.

Add chicken to pot, and simmer 10 to 15 minutes, until chicken is just cooked through.

Whisk in coconut milk and return to a simmer to heat through (do not boil).

Turn off heat and stir in spinach until it starts to wilt.

Season with salt and pepper and sprinkle with cilantro before serving.